I've been avoiding this one, seems there's many opinions on what's really happening with this issue. Plus, I got flamed royally on another site for simply relaying some info I found out, including questioning my abilities as a mechanic.
Now, I asked around, particularly, I asked the machinist that did my 235. he has well over 50 years doing machine work, and has seen more engines that I care to count. From what he told me, there's more to it than just an oil additive problem. Somewhare, tha cam manufacturers have gotten sloppy, be it not propely hardening the cams or incorrect lifters. There could be issues with incorrect installation in some cases, too. Valves set too tight will make a lobe go flat, as will exessive spring pressures. Not saying that anyone here has done that!
One thing I find odd is the suggestion of using deisel grade oil to protect flat tappets, seeing as virtually all deisels have used roller lifters since the '40s.
Now, I'm not saying anyone is wrong. I just believe that there's more to it than just the oil. As for myself, I'm sticking with Valvoline Super HPO 30 wt. I checked the Valvoline site, it seems to have a higher Zinc amount than other oils, and they haven't changed it for '07.
